An equation for the calculation of true shear strain was derived from the integration of infinitesimal shear strain in plane shearing process with constant principal shear strain direction.
对切应变主轴不变的平面简单切变过程，通过无穷小应变的积分，导出了真实切应变计算公式。
2
Then the principalstrain measurement and forming safety margin prediction in defect regions are conducted.
接着对缺陷区域进行主应变测量和安全成形裕度预测。
3
This paper introduces a new way for defining the maximum principalstrain direction in plane strain condition.